Resultado da pesquisa (2)
Termo utilizado na pesquisa calcitriol
#1 - Thymic atrophy in cattle poisoned with Solanum glaucophyllum, p.266-274
Abstract in English:
ABSTRACT.- Fontana P.A., Zanuzzi C.N., Barbeito C.G., Gimeno E.J. & Portiansky E.L. 2009. Thymic atrophy in cattle poisoned with Solanum glaucophyllum. Pesquisa Veterinária Brasileira 29(3):266-274. Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, Calle 60 y 118, 1900 La Plata, Argentina. E-mail: elporti@fcv.unlp.edu.ar
Solanum glaucophyllum (Sg) [= S. malacoxylon] is a calcinogenic plant inducing “Enzootic Calcinosis” in cattle. The 1,25-dihydroxyvitamin D3, its main toxic principle, regulates bone and calcium metabolism and also exerts immunomodulatory effects. Thymocyte precursors from bone marrow-derived progenitor cells differentiate into mature T-cells. Differentiation of most T lymphocytes is characterized not only by the variable expression of CD4/CD8 receptor molecules and increased surface density of the T cell antigen receptor, but also by changes in the glycosylation pattern of cell surface glycolipids or glycoproteins. Thymocytes exert a feedback influence on thymic non-lymphoid cells. Sg-induced modifications on cattle thymus T-lymphocytes and on non-lymphoid cells were analysed. Heifers were divided into 5 groups (control, intoxicated with Sg during 15, 30 or 60 days, and probably recovered group). Histochemical, immunohistochemical, lectinhistochemical and morphometric techniques were used to characterize different cell populations of the experimental heifers. Sg-poisoned heifers showed a progressive cortical atrophy that was characterized using the peanut agglutinin (PNA) lectin that recognizes immature thymocytes. These animals also increased the amount of non-lymphoid cells per unit area detected with the Picrosirius technique, WGA and DBA lectins, and pancytokeratin and S-100 antibodies. The thymus atrophy found in intoxicated animals resembled that of the physiological aging process. A reversal effect on these changes was observed after suppression of the intoxication. These findings suggest that Sg-intoxication induces either directly, through the 1,25-dihydroxyvitamin D3 itself, or indirectly through the hypercalcemia, the observed alteration of the thymus.
Abstract in Portuguese:
ABSTRACT.- Fontana P.A., Zanuzzi C.N., Barbeito C.G., Gimeno E.J. & Portiansky E.L. 2009. Thymic atrophy in cattle poisoned with Solanum glaucophyllum. Pesquisa Veterinária Brasileira 29(3):266-274. Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, Calle 60 y 118, 1900 La Plata, Argentina. E-mail: elporti@fcv.unlp.edu.ar
Solanum glaucophyllum (Sg) [= S. malacoxylon] is a calcinogenic plant inducing “Enzootic Calcinosis” in cattle. The 1,25-dihydroxyvitamin D3, its main toxic principle, regulates bone and calcium metabolism and also exerts immunomodulatory effects. Thymocyte precursors from bone marrow-derived progenitor cells differentiate into mature T-cells. Differentiation of most T lymphocytes is characterized not only by the variable expression of CD4/CD8 receptor molecules and increased surface density of the T cell antigen receptor, but also by changes in the glycosylation pattern of cell surface glycolipids or glycoproteins. Thymocytes exert a feedback influence on thymic non-lymphoid cells. Sg-induced modifications on cattle thymus T-lymphocytes and on non-lymphoid cells were analysed. Heifers were divided into 5 groups (control, intoxicated with Sg during 15, 30 or 60 days, and probably recovered group). Histochemical, immunohistochemical, lectinhistochemical and morphometric techniques were used to characterize different cell populations of the experimental heifers. Sg-poisoned heifers showed a progressive cortical atrophy that was characterized using the peanut agglutinin (PNA) lectin that recognizes immature thymocytes. These animals also increased the amount of non-lymphoid cells per unit area detected with the Picrosirius technique, WGA and DBA lectins, and pancytokeratin and S-100 antibodies. The thymus atrophy found in intoxicated animals resembled that of the physiological aging process. A reversal effect on these changes was observed after suppression of the intoxication. These findings suggest that Sg-intoxication induces either directly, through the 1,25-dihydroxyvitamin D3 itself, or indirectly through the hypercalcemia, the observed alteration of the thymus.
#2 - Ultrastructural alterations of bone cells in the experimental Solanum malacoxylon poisoning in rabbits
Abstract in English:
The ultrastructure of bone cells of mid-diaphysis of the humerus of young rabbits that received by gastric tube a water estract of Solanum malacoxylon corresponding to 100 mg/kg of body weight is described. Atrophic, degenerated and necrotic osteocytes anel mineralization of perilacunar osteoiel were the main lesions. Osteoblasts were atrophic with diminution of synthetic organels. Osteoclasts exhibited a ruffle border in dose contact with the non eroded mineralized matrix, poorly developecl vesicular region and absent clear zone. Macrophages in fusion forming multinucleated giant cells wcre seen in some resorption cavities. It is suggested that the 1,25(OH)2D3 present in the plant is responsible for the cell changes, inhibition of osteoclastic and osteocytic resorption anel osteopetrosis.
Abstract in Portuguese:
É descrita a ultra-estrutura das células ósseas da cortical da diáfise do úmero de coelhos jovens que receberam, diariamente, via sonda gástrica, um extrato aquoso de Solanum malacoxyloncorrespondente a 100mg da planta seca por quilograma de peso corporal e foram sacrificados 96 horas após o início do experimento. Osteócitos mostravam diversos graus de atrofia e necrose. Lacunas osteocíticas com restos celulares ou vazias foram vistas com frequência. Mineralização do tecido osteóide perilacunar foi constantemente observada. Os osteoblastos mostravam atrofia, diminuição das organelas de síntese e, em algumas oportunidades, exibiam núcleos picnóticos e estavam livres nos canais de Havers. Os osteoclastos mostravam borda pregueada em íntimo contato com a matriz mineralizada não erodida, região vesicular pouco desenvolvida e ausência da zona clara na periferia da borda pregueada. Em alguns canais de Havers, foram identificados macrófagos em processo de fusão para formarem células gigantes. Sugere-se que a osteopetrose descrita na intoxicação por S. malacoxylon seja decorrente de inibição das atividades de reabsorção osteocítica e osteoblástica, por efeito direto da ação de 1,25(OH)2D3.
